False twist crimping apparatus



Aug. 26, 1969 NAVA FALSE TWIST CRIMPING APPARATUS Original Filed Oct. 2,1965 2 Sheets-Sheet l Aug. 26, 1969 M. NAVA 3,462,933

FALSE TWIST CRIMPING APPARATUS Original Filed Oct. 2, 1963 2Sheets-Sheet? FIG.3

INVENTOR mama 0A wax/#4 ATTORNEY United States PatentOffice US. Cl.57-34 15 Claims ABSTRACT OF THE DISCLOSURE False twisting meansfalse-twists a thermoplastic yarn while the same is maintained at arelatively low temperature below its melting point. This results in apartially set false twist crimped yarn having a high contractibilityexceeding 50%. Delivery means is operatively associated with the falsetwisting means for delivering the yarn from the same at a predeterminedspeed. Collecting means is operatively associated with the deliverymeans for collecting the thus delivered yarn on a take-up package, butat a speed less than the predetermined delivery speed so that thetension of the yarn is reduced while, however, the yarn is stillmaintained under substantial tension when it reaches the take-uppackage. Finally, setting means is provided for treating the thuswound-up yarn with a setting fluid for a given period of time so as tocomplete the setting of the yarn, thus obtaining a relaxed false twistcrimped yarn which has only a low contractibility of substantially lessthan 50%, has substantial dimensional stability and is substantially ofthe non-torque type while being almost as highly bulked as fully twistcrimped yarn.

Cross-references to related applications This application is a divisionof my copending application Ser. No. 554,209, filed May 31, 1966, nowUS. Patent No. 3,316,705, which, in turn, is a continuation ofapplication Ser. No. 313,392, filed Oct. 2, 1963, now abandoned, which,in turn, is a continuation-in-part of application Ser. No. 12,536, filedMar. 8, 1960, now abandoned, which, in turn, is a continuation-in-partof application Ser. No. 812,744, filed May 12, 1959, now abandoned, andapplication Ser. No. 782,536, filed Dec. 23, 1968, now abandoned.

Background of the invention The present invention relates to anarrangement for producing artificial yarns. More particularly, theinvention relates to an arrangement for producing an artificial yarnwhich is only contractile to the extent of less than 50% and which isalmost as highly bulked as fully twist crimped yarn.

It is known to manufacture bulked yarn by twisting the yarn and settingthe twist therein, as, for example, by heating the yarn and untwistingthe same. In this manner the individual yarns which originally aresubstantially straight become crimped and thus the yarn is bulked. Theseyarns are highly contractile, for example, to the extent of ZOO-350%. Inother words, when the yarn is held straight but not stretched to such anextent that it will break, and then released, the yarn will contract inlength from ZOO-350%. Yarn of this type is extremely useful in themaking of articles such as stretch socks or 3,462,933 Patented Aug. 26,1969 other stretch garments, but such yarns have uneven shrinkageproperties and do not have dimensional stability when knitted or wovenso that it becomes necessary to further treat these yarns, thusincurring undesirable inconvenience and expenses. In other words, inorder to render such yarns suitable for Warp knitting and also forweaving, the yarns must undergo the long and rather expensive processesof stapling, drafting and spinning.

The disadvantages outlined above could be overcome by providing a yarnwhich, While almost as highly bulked as a fully twist crimped yarn, isnevertheless contractile to an extent substantially less than 50%, andwhich is preferably contractile to an extent of only 10-20%. However noarrangement capable of producing such a yarn has become knownherebefore.

Summary of the invention The present invention overcomes theabove-outlined disadvantages of the prior art, and makes it possible tomanufacture a yarn having the desired properties, by providing anarrangement capable of manufacturing such a yarn and not heretoforeknown in the art.

More particularly, the present invention provides an arrangement for theproduction of a yarn which, while almost as highly bulked as a fullytwist crimped yarn, nevertheless is contractile to an extentsubstantially less than 50%.

Furthermore, the novel arrangement in accordance with the presentinvention makes possible the production of a yarn of the type outlinedabove in a rapid and inexpensive manner from any thermoplastic yarn,even such thermoplastic yarns as in the past have presented difficultiesin working.

Furthermore, the novel arrangement in accordance with the presentinvention is also particularly suitable for handling a soft-yarn packagein order to subject the same to the influence of a setting fluid.

The novel arrangement is also easily regulatable so that it can beadapted to the treatment of any thermoplastic yarn, and is not limitedto the treatment of any particular type of such yarn.

Furthermore, the arrangement in accordance with the present inventionalso includes an extremely simple and efiicient structure for applyingheat to the yarn during the treatment of the latter.

In accordance with these and other features of my invention I provide anarrangement for producing a yarn which is only contractile to the extentof substantially less than 50% and which is almost as highly bulked asfully twist crimped yarn. My novel arrangement comprises false twistingmeans for false twisting a thermoplastic yarn and for Only partiallysetting the yarn for maintaining the same during the false twisting at arelatively low temperature below the melting point of the thermoplasticyarn so as to obtain a partially set false twist crimped yarn which hasa high contractibility exceeding 50%. Furthermore, my novel arrangementcomprises delivering means which is operatively associated with thefalse twisting means, and such delivering means delivers the partiallyset false twist crimped yarn from the false twisting means at apredetermined speed. Collecting means are provided which are operativelyassociated with the delivering means for collecting the partially setfalse twist crimped yarn, which is delivered from the false twistingmeans at the aforementioned predetermined speed, and for collecting thisyarn on a take-up package at a speed which is less than thispredetermined delivery speed, whereby the tension of the thus-collectedyarn is reduced while the yarn is, however, still retained atsubstantial tension when it reaches the take-up package so that it iswound up onto the latter still under substantial tension. Finally, mynovel arrangement includes setting means for treating the yarn which isthusly wound onto the takeup package, and this setting means includesmeans for subjecting the yarn for a given period of time to theinfluence of a setting fluid so as to complete the setting of thepartially tensioned, partially set false twist crimped yarn. With thisarrangement I obtain a relaxed false twist-crimped yarn which has only alow contractibility of substantially less than 50%, which hassubstantial dimensional stability, and which is substantially of the nontorque type While being almost as highly bulked as fully twist crimpedyarn.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe has understood from the following description of specific embodimentswhen read in connection with the accompanying drawings.

Brief description of the drawing FIG. 1 is a diagrammatic illustrationof an arrangement in accordance with the present invention;

FIG. 2 is a view of FIG. 1 as seen in the direction of the arrow in FIG.1;

FIG. 3 is a further illustration of the arrangement shown in FIGS. 1 and2, as described in greater detail; and

FIG. 4 is a diagrammatic illustration of the manner in Which a soft yarnpackage produced with the apparatus shown in FIG. 1 is enveloped in acheesecloth covering prior to introduction of such package into anautoclave.

Description of the preferred embodiments Referring now to the drawing,and more particularly to FIGS. 1-3, it will be seen that the yarn whichis to be treated is derived from a supply package which is supported ina conventional manner. Thus, the yarn can be drawn upwardly from thesupply package 10 and it will be understood that this yarn may be anythermoplastic yarn as it is received ready for false twisting. Thus, forexample, the yarn which is identified with reference numeral 11 may benylon of 60 denier or it may be 60 denier Terylene, the latter being thetrade name for the fiber forming synthetic linear polymeric condensationproduct of terephthalic acid and ethylene glycol, and the yarn is of thecontinuous multifilament type.

The thermoplastic yarn 11 is drawn upwardly from the supply package 10by a feed roll means including a lower driven roll 12 and an upperrubber-covered roll 13 which latter simply rests with its own weight onthe driven roll 12 as seen in FIG. 3. The roll 12 is dirven by anysuitable motor through any suitable gearing or the like, and it is notbelieved to illustrate this driving means since it is entirelyconventional. Driving of the roll 12 is so adjusted as to produce adesired speed of movement of the yarn 11 along the path which isillustrated in FIG. 1. The roll 13 is supported, as clearly evident fromFIG. 3, for turning movement by a shaft 14 which extends between and isfixedly carried by a pair of arms 15 which latter are parallel to eachother and only one of which is shown in the drawing. These arms 15 arepivotally supported by a bracket 16 carried by the stationary framework17 which is only diagrammatically illustrated in the drawing.

The arms 15 extend beyond the shaft 14 and are interconnected at theirends distant from the brackets 15 by a spacer bar 18 which is fixed tothe arms 15 and which is formed with a plurality of notches so that theyarn 11 may be wound a desired number of times around the roll 13 witheach loop of the yarn passing around the space bar 18 and the severalloops respectively being located in the notches of this bar. Thisassures that the several loops cannot become fouled, and the yarn whichpasses into the nip between the rolls 12 and 13 and is then wound adesired number of times around the roll 13 in the manner described abovethereupon passes upwardly to the false twisting means 20. This latter isin the form of any conventional false twist spindle driven in a purelyconventional manner and it is not believed necessary to describe this inmore detail since it will be readily evident to those of ordinary skillin the art.

The yarn 11 is received above the false twisting means 20 by aforwarding roll means 21 whose construction is identical with that ofthe feed roll means described below and the yarn is again wound in thesame way, after passing to the nip between the rolls of the forwardingroll means 21, a desired number of times around the upper rubber-coveredroll so as to provide a desired number of flukes which are alsoprevented from fouling by a spacer bar, just as described above relativeto the feed roll means. The forwarding rolls advance the yarn onto atake-up package in a manner which will be described subsequently.

During the false twist crimping of the yarn, the tension thereof isregulated by providing a speed of the yarn at the forwarding roll means21 which has a predetermined ratio with respect to the speed given tothe yarn by the feed roll means. Preferably, this tension is controlledin such a way that the yarn is allowed to contract by approximately 3%during the twisting thereof, the permitted contraction being determinedby the kind of yarn which is utilized.

The twist is only partially set in the yarn by applying a relatively lowtemperature thereto, and for this purpose a heating means 22 is providedwhich includes a curved heating surface 23. This curved heating surface23 has been found to be of considerable advantage since it veryuniformly heats the yarn as the latter moves rapidly past the surface 23which is illustrated in FIG. 3 as being heated by a heating coil 24. Inpractice it has been found that the relatively low temperature appliedto the yarn by the heating means 22 need not be maintained precisely.Putting this ditferently, it has been found that the temperature mayvary considerably without producing any detrimental results in the finalproduct. It is, however, essential to provide a relatively lowtemperature of approximately 50 less than the melting temperature of theyarn. The temperature applied to the yarn by the heating means 22 may,for example, be 60 less than the melting temperature of the yarn.

FIG. 3 illustrates that the temperature can be controlled by connectingthe heating coil 24 to the secondary winding of a step transformer 25having a series of taps, any one of which may be selectively used forregulating the temperature of the heating means 22. The secondarywinding 25 cooperates with the primary winding 26 which is supplied withcurrent from the main.

The partially set yarn, forwarded by the delivery or forwarding rollmeans 21, is received by a package forming arrangement 30 which includesa driven lower roll 31. The package 32 which is being formed in thismanner rests on the driven roll 31 and the yarn is collected onto thepackage 32 whose diameter of course increases during the collecting ofthe yarn. The yarn is distributed along the take-up package 32 by aconventional traverse mechanism 33 which will be well known to thoseconversant with this art. The yarn of the take-up package 32 is woundonto a tubular core capable of moving vertically, this core being guidedby the vertical guides 35 of the framework which is diagrammaticallyillustrated in FIG. 3.

In accordance with the present invention the speed at which the yarn istaken up onto the take-up package 32 is substantially less than thespeed of the yarn at the delivery or forwarding roll means 21. However,the speed at which the yarn is taken up onto the take-up package 32 isnot so much less that there is no tension at all in the yarn reachingthe take-up package. Rather, the speed of the yarn at the take-uppackage, which speed is controlled by the speed of rotation of the roll31, is on the order of -30 less than the speed of the yarn at theforwarding or delivery roll means 21. This assures that the package 32is quite soft. In accordance with the invention it is preferred tocontrol the yarn by the degree of overfeed rather than by any tensioningdevice. In other words, while the yarn is under tension when reachingthe take-up package, the tension is not of a very high order which wouldmake it feasible to control the speed of movement of the yarn to thetake-up package by a suitable tensioning device. By providing anoverfeed of the yarn traveling to the take-up package it is possible tovery precisely control the degree to which the yarn is tensioned as itreaches the take-up package without relying on any particular tensioningdevices which could only provide a greater tension than is actuallydesired. Thus, reference is made herein to the degree of overfeed,namely an overfeed which will provide at the take-up package a speed oftravel of the yarn which is on the order of 10-30% less than the speedof the yarn at the forwarding or delivery roll means 21, because in theactual performance of the operations the controls are carried outprecisely in this way rather than by maintaining a particular tension inthe yarn.

This soft package of partially set yarn thus obtained is removed fromthe framework 35 and is introduced into an autoclave 36 for finalsetting. After the autoclave is evacuated, it is filled with steam sothat the soft yarn package is influenced by the setting fluid, and thesteam is applied at a pressure of 2-3 atmospheres for a period of halfan hour. Thereafter, the yarn remains in an atmosphere of at least 50%humidity at room temperature for a period of twenty-four hours.

In accordance with the invention, the yarn package 32 is enveloped in alength of cheesecloth 37 as shown in FIG. 4, before the package isplaced into the autoclave. To accomplish this, the length of cheesecloth37 which may be of approximately rectangular configuration, is insertedthrough the hollow center of the soft yarn package, and then the ends ofthe cheesecloth 37 are drawn around the package into an overlyingrelation, as indicated diagrammatically in FIG. 4, whereupon a string 38is tied around the thus-enveloped package, and in this manner the softpackages are extremely easy to handle and at the same time thecheesecloth does not in any way detract from the accessibility of theyarn to the setting fluid in the autoclave.

Yarn produced with the above-described arrangement in accordance withthe present invention is almost as highly bulked as a fully twistcrimped yarn and at the same time it is contractile to an extent of lessthan 50%, and in actual operating experience it has been found to becontractile to an extent on the order of 10 20%. As indicated earlier,the yarn which is wound onto the takeup package is still under asubstantial tension. The filaments of the yarn, when wound onto thetake-up package, have a partially spiral or undulator formation andthese filaments remain separate from one another without tending totwist on themselves or to pigtaiP so that the yarn is set in this lattercondition. Thus, the final yarn has such filaments when the tension onthe yarn is relaxed and the yarn is in a stabilized or yarnsetcondition, and in addition it is substantially free from torque. Thesignificance of the yarn produced in this manner is immediately evidentwhen one considers that the yarn has considerable dimensional stabilitywithout sacrificing in any Way the highly bulked characteristics whichare desirable. Thus, the yarn produced by the arrangement according tothe present invention can immediately be used for knitting or weavingand all of the undesirable further processing required for conventionalbulked yarn to give it dimensional stability is completely avoided.Furthermore, yarn produced by the arrangement according to the presentinvention is substantially non-torque, which means that it need not bedoubled with an oppositely twisted yarn in order to providecounterbalancing of the torques, and thus the yarn produced with thearrangement of the present invention can be a simple single yarn, afeature which also represents a great advantage over the known state ofthe art.

The partial setting provided by the heating means 22 v is rendered justthat, namely partial, by the fact that the crimp induced by the falsetwister is not permanently set in the yarn with the heating means 22. Inother words, if the yarn is straightened and permitted to contract a fewtimes when influenced only by the heating means 22, it will be foundthat the yarn will simply lose its crimp after a relatively small numberof extensions, whereas, if the crimp were permanently set, any number ofextensions of the yarn could be carried out without eliminating thecrimping.

In utilizing Terylene of 75 denier with an arrangement according to thepresent invention, a soft lively yarn was produced when feeding the yarnat a speed of 12-18 meters per minute through the false twister so as toproduce a crimp of 55-80 turns per inch. The heating means 22 wasutilized for applying a temperature of -140" C. to the yarn, and in theautoclave the yarn was subjected for 15-45 minutes to steam at 20-30pounds per square inch pressure.

Utilizing nylon yarn in the arrangement according to the presentinvention, the temperature applied by the heating means 22 was as low as70 C., but never more than C. When using a high speed machine, thefeeding speed for Terylene may be as high as 80 meters per minute, andin this case the temperature applied by the heating means 22 may be ashigh as 215 C. The temperature applied tothe yarn by the heating means22 is such that for the particular yarn speed which is used thethermoplastic filaments become sufficiently hot so as to be renderedplastic, which is to say readily deformable by relatively small forces.This is so because, as outlined earlier, the crimp need only betemporarily or partially set by the heating means 22 since the actualsetting takes place in the autoclave 36.

The advance which the arrangement hereindisclosed represents in thestate of this art is evident to those who are skilled in this art. Itbecomes particularly clear when a yarn produced according to theinvention is compared with a known false twist crimped bulked yarn. Suchcomparisons have been made, and after knitting both such yarns intofabric these fabrics have been compared. In both cases the bulked yarnwas two fold denier, and on comparison it was found that the fabric madefrom a yarn produced with an arrangement according to the presentinvention weighed 6.9 ounces per square yard while that madeconventionally weighed 8.6 ounces per square yard, but at the same timethe covering power and bulky feel of the yarn of the invention wasidentical with that of the conventional yarn.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofarrangements differing from the types described above.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. An arrangement for producing a yarn which is only contractile to theextent of substantially less than 50% and which is almost as highlybulked as fully twist crimped yarn, said arrangement comprising, incombination, false twisting means for false twisting a thermoplasticyarn and twist setting means for only partially setting the yarn bymaintaining the same during said false twisting at a relatively lowtemperature below the melting point of said thermoplastic yarn so as toobtain a partially set false twist crimped yarn which has a highcontractibility exceeding 50%; delivering means operatively associatedwith said false twisting means for delivering said partially set falsetwist crimped yarn having high contractibility from said false twistingmeans at a predetermined first speed; collecting means associated withsaid delivering means and operative for collecting said partially setfalse twist crimped yarn having high contractibility on a take-uppackage at second speed which is less than said predetermined firstspeed of de-' livery so that the tension of said partially set twistcrimped yarn having high contractibility is reduced, but which secondspeed is still great enough to retain substantial tension in said thusonly partially tensioned partially set false twist crimped yarn havinghigh contractibility when the same reaches said take-up package, so thatsaid partially tensioned partially set false twist crimped yarn of highcontractibility is wound up on said take-up package still undersubstantial tension; and additional setting means for treating saidpartially tensioned partially set false twist crimped yarn having highcontractibility wound up under said substantial tension on said take-uppackage, for a given period of time with a setting fluid so as tocomplete the setting of said partially tensioned partially set falsetwist crimped yarn, thus obtaining a relaxed false twist crimped yarnwhich has only a low contractibility of substantially less than 50%, hassubstantial dimensional stability and is substantially of the non-torquetype while being almost as highly bulked as fully twist crimped yarn.

2. An arrangement as defined in claim 1, wherein said delivering meansincludes means for controlling said predetermined first speed.

3. An arrangement as defined in claim 1; and further comprising yarnsupply means arranged below said false twisting means for supplying yarnto the latter in upward direction.

4. An arrangement as defined in claim 1, wherein said twist settingmeans comprise heating means for heating said yarn to an elevatedtemperature below the melting point thereof.

5. An arrangement as defined in claim 4, wherein said heating means arearranged for heating said yarn to between 100 and 140 centigrade.

6. An arrangement as defined in claim 4, wherein said heating means arearranged for heating said yarn to an elevated temperature ranging up to215 Centigrade.

7. An arrangement as defined in claim 1, wherein said additional settingmeans include an autoclave, evacuating means for reducing the pressurein said autoclave, and setting fluid supply means for introducingsetting fluid into said autoclave.

8. An arrangement as defined in claim 1, wherein said delivering meansincludes means for controlling said predetermined first speed withinsuch a range that such predetermined second speed is substantiallygreater than the second speed at which said yarn is collected on saidtakeup package, so as to thereby obtain a soft take-up package.

9. An arrangement as defined in claim 8, wherein said means forcontrolling said predetermined speed enables varying of the latterwithin such a range that the second speed at which said yarn iscollected on said take-up package is between 10% and 30% lower than saidpredetermined first speed.

10. An arrangement as defined in claim 1, wherein said additionalsetting means include means for maintaining said take-up package at apredetermined pressure during said given period of time.

11. An arrangement as defined in claim 1, wherein said additionalsetting means comprise evacuable chamber means arranged to accommodatesaid take-up package.

12. An arrangement as defined in claim 11, wherein said additionalsetting means further comprise means for increasing pressure within saidchamber means to a range between 2 and 3 atmospheres.

13. An arrangement as defined in claim 1, wherein said collecting meanscomprises winding means for winding said yarn on said take-up package insuch manner that the filaments of said yarn remain separate from eachother and without tending to twist on themselves.

14. An arrangement as defined in claim 1, wherein said false twistingmeans is arranged for false twisting said yarn at a rate of advancementranging between 12 and 18 meters per minute.

15. An arrangement as defined. in claim 1, wherein said false twistingmeans is arranged for false twisting said yarn at a rate of advancementranging up to meters per minute.

References Cited UNITED STATES PATENTS 2,421,334 5/1947 Kline et al.57l57 XR 2,869,318 l/l959 Stucki 57-l57 FOREIGN PATENTS 755,580 8/1956Great Britain.

JOHN PETRAKES, Primary Examiner US. Cl. X.R. 57l57 "H050 UNITED STATESPATENT OFFICE Patent No. 3,462,933

Inventor-(s) Mario Nava Dated August 26, 1969 It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Claim 8, line 4, first is substituted for "second".

SIGNED AND SEALED FEB 2 41970 4 Edward u w I vim-1m mm. m. Anestin: offiGomiaaioaar at Patents

